-- Created on: 2021-03-15
-- Created by: Stephan GARNAUD (ARM)
-- Copyright (c) 1998-1999 Matra Datavision
-- Copyright (c) 1999-2012 OPEN CASCADE SAS
--
-- The content of this file is subject to the Open CASCADE Technology Public
-- License Version 6.5 (the "License"). You may not use the content of this file
-- except in compliance with the License. Please obtain a copy of the License
-- at http://www.opencascade.org and read it completely before using this file.
--
-- The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
-- main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
--
-- The Original Code and all software distributed under the License is
-- distributed on an "AS IS" basis, without warranty of any kind, and the
-- Initial Developer hereby disclaims all such warranties, including without
-- limitation, any warranties of merchantability, fitness for a particular
-- purpose or non-infringement. Please see the License for the specific terms
-- and conditions governing the rights and limitations under the License.






class SharedMemory from OSD 

   ---Purpose: IPC Tools -Shared Memory
   --          This is a low level interface for communications.
   --          Using shared memory, processes can use a common area to
   --          communicate.
   --          You can create and delete a shared memory.

uses Error, AsciiString from TCollection
raises ConstructionError, NullObject, OSDError, ProgramError
   

is
  Create returns SharedMemory;
    ---Purpose: Allocates room for shared memory name.
    --          This is to be used with 'Open'.
    --          In this case, the process is a client of shared memory.
    ---Level: Advanced

  Create (Name : AsciiString ; size : Integer) returns SharedMemory
    ---Purpose: Instantiates SharedMemory object with parameters.
    --          A name to make sure shared memory is unique and a size in
    --          bytes for the size of shared memory.
    --
    --          Raises ConstructionError when the name contains characters 
    --          not in range of ' '...'~'.
    --          Raises ProgramError when the size given is negative or null.
    --          This is for a server process.
    --          
    ---Level: Advanced
    raises ConstructionError, ProgramError;

  Build (me : in out)  is static;
    ---Purpose: Creates a shared memory in the system
    --          This is for a server process.
    ---Level: Advanced

  Open (me : in out ; Name : AsciiString ; size : Integer)
    ---Purpose: Opens a shared memory
    --          Raises ConstructionError when the name contains characters 
    --          not in range of ' '...'~'.
    --          Raises ProgramError when the size given is negative or null.
    --          This is for a server process.
    --          
    ---Level: Advanced
    raises ConstructionError, ProgramError is static;

  Delete (me : in out)
    ---Purpose: Removes a shared memory access.
    --          This is used only by a server process !
    ---Level: Advanced
    raises ProgramError is static;

  GiveAddress (me) returns Address
    ---Purpose: Returns address of shared memory.
    --          Raises NullObject when the Shared Memory is not created.
    ---Level: Advanced
    raises NullObject is static;

  Failed (me) returns Boolean is static;
    ---Purpose: Returns TRUE if an error occurs
    ---Level: Advanced

  Reset (me : in out) is static;
    ---Purpose: Resets error counter to zero
    ---Level: Advanced
      
  Perror (me : in out)
    ---Purpose: Raises OSD_Error
    ---Level: Advanced
    raises OSDError is static;

 Error (me) returns Integer is static;
   ---Purpose: Returns error number if 'Failed' is TRUE.
    ---Level: Advanced

fields
   myId : Integer;     -- Shared memory ID
   myAddress    : Address;
   myName : AsciiString;   
   mySize : Integer;
   myError : Error;
end SharedMemory from OSD;